Some years back practically all internal combustion powered vehicles had a fuel pump in the engine compartment which drew fuel from a remote fuel tank and furnished fuel to the engine. More recently the use of fuel pumps in the fuel tank has become common and in most cases the fuel pump is mounted in a fuel canister with special valving to provide fuel supply to the pump inlet from the canister when the supply is low in the main fuel tank. U.S. Pat. No. 4,747,388 issued May 31, 1988 to the assignee of the present invention is an example of this system. This structure provided fuel to the pump inlet when the pump inlet was starved because of low fuel or because of movement of fuel in the main tank to one side during the negotiating of a curve.
However, there are still some vehicles manufactured which have a fuel pump in the engine compartment. Some diesel powered vehicles are examples, and also other vehicles where two tanks are used, and it would be inappropriate to put a fuel pump in each tank.
In these instances where the fuel pump in the engine compartment and remote from the fuel tanks, there may be still a problem when there is a low fuel supply, to keep fuel going to the pump. This could happen when a vehicle is exiting or entering an expressway and executing a 270.degree. turn at a relatively high speed. The centrifugal force can force the fuel to one side of the tank and starve the fuel pick-up point at the tank. This can cause the engine to sputter or quit.
The present invention is directed to an in-tank valve located in a canister in the main fuel tank at the fuel pick-up point. The fuel canister is supplied with fuel from a fuel return line leading from a pressure regulator valve.
It is an object to provide what may be termed an "attitude activated valve" which is responsive to centrifugal force resulting from a vehicle negotiating a corner or curve. In repose, during normal operation, the valve element, which can be responsive to a lateral force, closes an auxiliary port and retains return fuel in the canister. In response to lateral force, the valve opens the auxiliary port and allows the fuel in the canister to dump into a fuel flow passage leading to the pump. This will occur whether the vehicle is turning to the right or to the left.
Other objects and features of the invention will be apparent in the following description and claims in which details of the invention are set forth to enable those skilled in the art to practice the invention, all in connection with the best mode presently contemplated for the invention.